If the invocation time for a boon is 1 minor action, it can be invoked only once as a minor action.

My confusion comes from the last sentence. It seems the last sentence imply that each boon invoked as minor action is considered separate, and you can invoke two or more boons as minor action.

For example, with Boon Focus II: Bolster and Boon Focus II: Barrier, I can invoke both boons at the same turn as minor action. I don't need to sustain both boons (first turn it is invoked is free) because (or as long as) I don't sustain any other boon.

I was expecting the opposite - you can only invoke one boon as minor action, because you can only take one kind of each minor action, in this case: Invoke Boon. The only way to get around this rule is to consider each separate invocation as different kind of minor action: Invoke Boon Barrier, Invoke Boon Bolster.

Can I invoke multiple boons in one turn using minor actions if I have two different Boon Focus II?

1 Answer
1

No, you can only take one type of minor action per turn

The description for minor actions is as follows (emphasis mine):

Minor actions are tasks that don’t require much time or effort, but
often set up larger actions. You may take any number of minor actions
on your turn, but you cannot take more than one of the same type of
minor action.

The wording is very vague, and does not specify what a type of minor action is (though it provides some examples, and invoking a boon is not one of them), but I would rule that invoking a boon would be a type of minor action, so you probably couldn't invoke two boons like that.

However, you can cast one minor action boon, sustain another (as this is a different kind of minor action), and cast another with your major action (this could not be a boon focus II boon, as the duration to cast it is one minor action, not a major action).